@obi1 I don’t really know why (or if) anything about DX11 would be fundamentally slower than DX9. I think for most people, with modern hardware and higher/default graphics settings, BMS did get faster.
I think what you’re seeing is the additional complexity of the theater-world in 4.35 (more buildings, bigger airbases, things like wind turbines, etc) and also higher level of detail, and changes in the way the engine computes lighting and shadows… eg. we lost the 4.34-era “per-vertex lighting” setting which was probably a benefit on your rig.
At the end of the day, the pace of development will surely continue to put increasing load on system reqs… not less. So it seems unavoidable that every major release will drop support for someone. But I actually think the BMS team is doing an admirable job of targeting a trailing ~10 year window of hardware compatibility… not going overboard with super-high detail cockpit textures etc, which are obviously available in the community.
Especially at a time when it’s so hard/expensive to acquire high-end CPU and GPU parts.